gNMI-1.14 TestPlan: OpenConfig metadata consistency during large conf…

…ig push (openconfig#2152)

* Create feature.textproto

* Create README.md

* draft 1

* cleanup

* 1st draft

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update feature/system/gnmi/metadata/tests/lagre_set_consistency_test/README.md

Co-authored-by: Darren Loher <[email protected]>

* Update README.md

---------

Co-authored-by: Darren Loher <[email protected]>
Co-authored-by: sachendras <[email protected]>

feature/system/gnmi/metadata/tests/lagre_set_consistency_test/README.md

@@ -0,0 +1,42 @@
+# gNMI-1.14 OpenConfig metadata consistency during large config push
+
+## Summary
+This test verify if OpenConfig metadata leaf at root is updated according to pushed config and not reverted or otherway modified, Even if many rapid, concurrent non-write requests are served while setRequest is in process (and SetResponse is not send yet).
+In case metadata leaf at root value changes, test fails.
+
+## Topology
+dut.testbed
+
+## Procedure
+
+* prepare 2 large OpenConfig configurations that only differs in root-level netadata/annotation - 1st_LARGE_CONFIGURATION and 2nd_LARGE_CONFIGURATION. Configuration should exercise following branches of Openconfig:
+  *  /interfaces/
+  *  /network-instances/
+  *  /qos/
+  *  /system/
+  *  /routing-policy/
+  *  /components/
+  *  /sampling/
+  *  /lldp/
+  *  /lacp/
+  *  /protobuf-metadata
+* Push 1st_LARGE_CONFIGURATION and wait for SetResponse that confirm push was sucesfull.
+* Send subscribe `ONCE` for configuration root-level metadata and verify that it is identical corresponding root-level metadata of 1st_LARGE_CONFIGURATION.
+* For REQUEST of type (GetRequest, SubscribeRequest, CapabilityRequest)
+  * Repeat sending rapidly subsequent REQUEST requests for configuration root-level metadata (GetRequest, SubscribeRequest).
+  * While above REQUESTS are send, push SetRequest replace with 2nd_LARGE_CONFIGURATION.
+  * After SetResponse is recived confirming sucesfull push of 2nd_LARGE_CONFIGURATION:
+    * stop sending REQUEST requests
+    * wait 5 seconds
+    * SubscribeRequest once for configuration root-level metadata and verify that it is identical corresponding root-level metadata of 2nd_LARGE_CONFIGURATION.
+
+## Configuration path coverage
+* /@/openconfig-metadata:protobuf-metadata
+
+> Note: WBB implementations need not support this annotation at paths deeper than the root (i.e., a configuration that contains openconfig-metadata:protobuf-metadata at any level other than under the root can be rejected). The WBB device implementation can map this to an internal path to store the configuration.
+
+## Telemetry path coverage
+* /@/openconfig-metadata:protobuf-metadata
+
+## Minimum DUT platform
+FFF